A9 Dominant 7th
The A9 chord is built from the notes A – C# – E – G – B.
Piano sound loads on first tap.
Also known as
A7add13A9add#11
Chord tones, one by one
ARoot
Root
The fundamental note the chord is built on — A.
C#Third
Major third
Four semitones — makes the chord major (brighter, happier).
EFifth
Perfect fifth
Seven semitones — the most stable interval, reinforces the root.
GSeventh
Minor seventh (♭7)
Ten semitones — the dominant/minor seventh. Adds bluesy tension (7, m7).
BExtension
Ninth (9)
A 9th — colorful extension a whole step above the octave.
🎼 Related scales
🎹 Modal analysis
This chord implies the Mixolydian scale; its characteristic note is the minor 7th (♭7).
🎸 Genres
Blues · Rock · Funk · Gospel
🎤 Artists who made it famous
James Brown